KR20200038227A - Time of flight camera apparatus - Google Patents

Abstract

A TOF camera apparatus according to one embodiment of the present invention includes: an optical output unit; an optical input unit including a plurality of pixels each of which includes a first reception unit and a second reception unit; a beam splitter including one surface which meets an optical axis of the optical output unit; and a calculation unit calculating the distance of an object by using light received by the optical input unit. The optical output unit outputs IR light flashing periodically, the first reception unit is activated while a light source is on, and the second reception unit is activated while the light source is off.

Description

TOF camera device {TIME OF FLIGHT CAMERA APPARATUS}

The present invention relates to a time of flight (TOF) camera device, and more particularly, to a depth information extraction of the TOF camera device.

Technology for obtaining a 3D image using a photographing apparatus has been developed. Depth map is required to acquire a 3D image. Depth information is information indicating a distance in space, and indicates perspective information of another point with respect to one point of a 2D image.

One of the methods of acquiring depth information is a method of projecting IR (Infrared) structured light onto an object, and extracting depth information by analyzing light reflected from the object. According to the IR structured light system, there is a problem that it is difficult to obtain a desired level of depth resolution for a moving object.

As a technology that replaces the IR structured light system, the TOF (Time of Flight) method is drawing attention. According to the TOF method, the distance from the object is calculated by measuring the flight time, that is, the time when the light is reflected by shooting.

In general, a camera that conforms to the TOF method (hereinafter referred to as a TOF camera) includes a scanner that adjusts the angle of light irradiated onto an object and a mirror that controls the path of light. Since such a TOF camera includes at least one folding mirror in order to control the path of light, the structure is complicated and there is a problem that it is difficult to implement it in a compact size.

The technical problem to be achieved by the present invention is to provide a TOF camera device for extracting depth information.

The TOF camera apparatus according to the embodiment includes an optical output unit, an optical input unit including a plurality of pixels, each of which includes a first receiving unit and a second receiving unit, a beam splitter including a surface that meets an optical axis of the optical output unit, and It includes a calculation unit for calculating the distance of the object using the light received by the light input unit, the light output unit outputs a flashing IR light with a period, the first receiving unit is activated while the light source is turned on, the The second receiving unit can be activated while the light source is turned off.

The light output unit may include a light conversion unit that modulates the input light and a light source that outputs light converted from the light conversion unit.

The light output unit may further include a light transmission member that transmits the output light to the beam splitter.

The first receiving unit and the second receiving unit may have different periods of receiving the light according to the distance between the objects.

The calculating unit may measure a distance between the object and the object using the difference in the amount of light received by the first receiving unit and the second receiving unit.

The beam splitter is disposed between the light output unit and the light input unit, transmits a portion of light, reflects the remaining portion, and incident at least a portion of the light output from the light output unit to the object to be reflected from the object. Light may be transmitted, and a part of the transmitted light may be transmitted to enter the light input unit.

The beam splitter and the light input unit may be arranged on an optical axis to which the light is transmitted.

Light transmitted through the beam splitter may be directly incident on the light input unit.

The ratio of transmittance to reflectance of the beam splitter may be 0.4 or more and 2.3 or less.

The TOF camera device further includes a scanner, and the scanner can adjust the angle of the IR light incident on the object.

The scanner can adjust the angle of light reflected from the object.

The beam splitter may incident at least a portion of the light output from the light output unit through the scanner to the object to cause light reflected from the object to enter the light input unit.

The TOF camera apparatus according to the embodiment includes an optical output unit, an optical input unit including a plurality of pixels, each of which includes a first receiving unit and a second receiving unit, a scanner for adjusting the angle of light incident on an object, and the optical input unit It includes a calculation unit for calculating the distance of the object using the received light, the light output unit outputs a flashing IR light with a period, the first receiving unit is activated while the light source is turned on, the second reception The unit can be activated while the light source is turned off.

The scanner may cause at least a portion of the light output from the light output unit to enter the object, and then the light reflected from the object may enter the light input unit.

According to an embodiment of the present invention, a TOF camera may be implemented in a small size. In addition, because of the high light efficiency, it is possible to precisely extract distance depth information and reduce power consumption.

1 is a block diagram of a TOF camera device according to an embodiment of the present invention.
2 is a block diagram of an optical output unit of a TOF camera device according to an embodiment of the present invention.
3 is a structure of an optical input unit of a TOF camera device according to an embodiment of the present invention.
4 is a diagram illustrating a method of calculating a distance of an object by a calculation unit of a TOF camera device according to an embodiment of the present invention.
5 shows a structure of a TOF camera device according to an embodiment of the present invention.

The present invention can be applied to various changes and can have various embodiments, and specific embodiments will be illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers such as second and first may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from other components. For example, the second component may be referred to as a first component without departing from the scope of the present invention, and similarly, the first component may also be referred to as a second component. The term and / or includes a combination of a plurality of related described items or any one of a plurality of related described items.

When an element is said to be "connected" or "connected" to another component, it is understood that other components may be directly connected to or connected to the other component, but may exist in the middle. It should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that no other component exists in the middle.

The terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "include" or "have" are intended to indicate the presence of features, numbers, steps, actions, components, parts or combinations thereof described herein, one or more other features. It should be understood that the existence or addition possibilities of fields or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings, but the same or corresponding components are assigned the same reference numbers regardless of reference numerals, and overlapping descriptions thereof will be omitted.

1 is a block diagram of a TOF camera device according to an embodiment of the present invention, FIG. 2 is a block diagram of an optical output part of a TOF camera device according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention It is a structure of an optical input unit of a TOF camera device according to an example, and FIG. 4 is a view for explaining a method of calculating a distance of an object by a calculation unit of a TOF camera device according to an embodiment of the present invention.

Referring to FIG. 1, the TOF camera apparatus 100 includes an optical output unit 110, an optical control unit 120, an optical input unit 130, and a calculation unit 140.

The light output unit 110 outputs infrared (IR) light. The IR light may be, for example, light having a wavelength band of 800 nm or more. Referring to FIG. 2, the light output unit 110 includes a light source 112 and a light conversion unit 114. The light source may include at least one laser diode or light emitting diode (LED) that projects infrared light. Also, the light conversion unit 114 may modulate light output from the light source 112. The light conversion unit 114 may, for example, pulse modulate or phase modulate the light output from the light source 112. Accordingly, the light output unit 110 may output by blinking the light source at a predetermined interval.

Referring back to FIG. 1, the light controller 120 controls modulation of light output from the light output unit 110. For example, the light control unit 120 may control pulse or phase modulation of light. The light controller 120 may control pulse or phase modulation of light according to a criterion preset by the user. For example, the light controller 120 may control pulse or phase modulation of light according to the brightness around the TOF camera device.

Meanwhile, the light input unit 130 receives light reflected from an object after being output from the light output unit 110. The optical input unit 130 may convert the received light into an electrical signal. The optical input unit 130 may be an image sensor including a photo diode or a complementary metal-oxide semiconductor (CMOS).

Referring to FIG. 3, the light input unit 130 includes a plurality of pixels 132 arranged. Each pixel may include an In Phase receiving unit 132-1 and an Out Phase receiving unit 132-2. 4, the In Phase receiving unit 132-1 is activated while the light source is turned on, and the Out Phase receiving unit 132-2 can be activated while the light source is turned off. As described above, when the In Phase receiving unit 132-1 and the Out Phase receiving unit 132-2 are activated with a time difference, a difference occurs in the amount of light received according to the distance to the object. For example, when the object is directly in front of the TOF camera device (that is, when the distance = 0), since the time it takes for light to be reflected after the light is output from the light output unit 110 is 0, the flashing cycle of the light source is It becomes the light reception cycle as it is. Accordingly, only the In Phase receiving unit 132-1 receives light, and the Out Phase receiving unit 132-2 cannot receive light. As another example, when the object is located at a predetermined distance from the TOF camera device, since light is output from the light output unit 110 and it takes time to reflect on the object, the flashing cycle of the light source is different from the light receiving cycle. do. Accordingly, a difference occurs in the amount of light received by the In Phase receiving unit 132-1 and the Out Phase receiving unit 132-2.

Referring back to FIG. 1, the calculating unit 140 calculates the distance of the object using the difference in the amount of light input to the In Phase receiving unit 132-1 and the Out Phase receiving unit 132-2.

According to an embodiment of the present invention, the TOF camera device further includes a scanner that adjusts the angle of light irradiated onto the object, and a transflective member that reflects a portion of the light and transmits the remaining portion. Accordingly, the optical layout distance is minimized, and the system can be made slim.

5 shows a structure of a TOF camera device according to an embodiment of the present invention.

Referring to FIG. 5, the light source 500 outputs IR light. The output IR light may be pulse or phase modulated light in the light conversion unit 502. The light source 500 may include, for example, a laser diode (LD) that outputs short wavelength light, a light emitting diode (LED), a light emitting diode having a multi-cell structure, and the like. .

IR light output from the light source 500 reaches the transflective member 520. The semi-transmissive reflection member 520 is disposed between the light source 500 and the light output unit 540 and the scanner 530, and transmits a portion of the light to reach and reflects the remaining portion.

At this time, the transflective member 520 may be a beam splitter (beam splitter).

The ratio of the transmittance to the reflectance of the transflective member 520 (transmittance / reflectance) may be 0.4 or more and 2.3 or less, preferably 0.7 or more and 1.5 or less. When the ratio of the transmittance to the reflectance of the transflective member 520 is outside this range, there is a lot of noise and the depth resolution may be deteriorated.

The transflective member 520 adjusts the path of at least a portion of the IR light output from the light source 500 to enter the scanner 530. Then, the scanner 530 adjusts the angle of the IR light output from the light source 500 and reflected by the transflective member 520. Accordingly, the angle of the IR light incident on the object can be adjusted, the front surface of the object can be scanned, and the light efficiency can be increased.

In addition, the scanner 530 adjusts the angle of light reflected from the object. Accordingly, light reflected from the object can efficiently reach the light input unit 540.

To this end, a separate driving device 532 may be connected to the scanner 530. The driving device 532 can rotate the scanner 530 at a high speed.

The light reflected from the object reaches the light input unit 540. The optical input unit 540 may include, for example, a photo diode (PD).

The light reaching the light input unit 540 is converted into an electrical signal, and the calculation unit 542 calculates the distance of the object using the converted electrical signal.

Meanwhile, according to an embodiment of the present invention, the transflective member 520 may be disposed between the light source 500, the scanner 530, and the light input unit 540. Accordingly, a part of the light output from the light source 500 is reflected and transmitted to the scanner 530. After being reflected from the object, a part of the light transmitted from the scanner 530 is transmitted to be incident on the light input unit 540. .

At this time, one surface of the semi-transmissive reflecting member 520 may be arranged to meet with the optical axis output from the light source 500. Then, the scanner 530, the transflective member 520, and the light input unit 540 may be arranged on the optical axis of light whose angle is adjusted by the scanner 530 after being reflected from the object. In this case, the light input unit 540 may be arranged so that light transmitted through the semi-transmissive reflecting member is directly incident without passing through an additional reflecting member. Accordingly, the optical path can be minimized to reduce the optical loss. In addition, spatial alignment between the pixel of the optical input unit 540 and the optical axis is easy, and the internal structure of the system can be slim.

Meanwhile, between the light source 500 and the transflective member 520, a light transmitting member 510 that transmits IR light output from the light source 500 to the transflective member 520 may be further disposed. The light transmitting member 510 may be, for example, a focusing lens.

According to an embodiment of the present invention, when the transflective member is disposed between the light output unit, the light input unit and the scanner, there is no need to arrange a folding mirror to control the path of light. Accordingly, light loss generated on the optical path is minimized, and the device can be implemented in a small size.

Although described above with reference to preferred embodiments of the present invention, those skilled in the art variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You can understand that you can.

100: TOF camera device
110: light output
120: light control
130: optical input
140: operation unit
500: light source
510: focusing lens
520: transflective member
530: scanner
540: PD

Claims (17)

Light output;
An optical input unit including a plurality of pixels, each of which includes a first receiving unit and a second receiving unit;
A beam splitter including a surface that meets the optical axis of the light output unit; And
It includes a calculation unit for calculating the distance of the object using the light received by the light input unit,
The light output unit outputs IR light blinking with a period,
The first receiving unit is activated while the light source is turned on,
The second receiving unit is a TOF camera device that is activated while the light source is turned off. According to claim 1,
The light output unit,
A light conversion unit that modulates the input light; And
TOF camera device including a light source for outputting the light converted from the light conversion unit. According to claim 2,
The light output unit,
TOF camera device further comprises a light transmitting member for transmitting the output light to the beam splitter. According to claim 1,
The first receiving unit and the second receiving unit
TOF camera device in which the reception cycle of the light is changed according to the distance to the object. According to claim 4,
The calculation unit,
TOF camera device for measuring the distance between the object using the difference in the amount of light received by the first receiving unit and the second receiving unit. According to claim 1,
The beam splitter,
It is disposed between the light output unit and the light input unit, transmits a portion of the light, reflects a portion of the light,
At least a part of the light output from the light output unit is incident on the object to receive light reflected from the object,
A TOF camera device that transmits a portion of the received light and enters the light input unit. According to claim 1,
The beam splitter and the light input unit are TOF camera devices arranged on an optical axis to which the light is transmitted. According to claim 1,
The light transmitted through the beam splitter is a TOF camera device directly incident on the light input unit. According to claim 1,
The ratio of transmittance to reflectance of the beam splitter is 0.4 or more and 2.3 or less. According to claim 1,
Further comprising a scanner, the scanner TOF camera device for adjusting the angle of the IR light incident on the object. The method of claim 10,
The scanner is a TOF camera device that adjusts the angle of light reflected from an object. The method of claim 10,
The beam splitter,
A TOF camera device in which at least a portion of light output from the light output unit through the scanner is incident on the object and light reflected from the object is incident on the light input unit. Light output;
An optical input unit including a plurality of pixels, each of which includes a first receiving unit and a second receiving unit;
A scanner that adjusts the angle of light incident on the object; And
It includes a calculation unit for calculating the distance of the object using the light received by the light input unit,
The light output unit outputs IR light blinking with a period,
The first receiving unit is activated while the light source is turned on,
The second receiving unit is a TOF camera device that is activated while the light source is turned off. The method of claim 13,
The scanner,
A TOF camera device in which at least a portion of light output from the light output unit is incident on the object and light reflected from the object is incident on the light input unit. The method of claim 13,
The scanner is a TOF camera device that adjusts the angle of light reflected from an object. The method of claim 13,
The first receiving unit and the second receiving unit
TOF camera device in which the reception cycle of the light is changed according to the distance to the object. The method of claim 16,
The calculation unit,
TOF camera device for measuring the distance between the object using the difference in the amount of light received by the first receiving unit and the second receiving unit.

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